The present invention relates to power transmission and more particularly to torque couplings for use in the transmission of rotational power.
The technology of power transmission through shaft couplings has not advanced significantly in recent times. Common practice has been to use splines, keys, or equivalent to retain the mated parts in fixed angular relation to each other. With splines or keys, the perimeters of the shaft and of the bore of its mate change abruptly in outline with the result that stresses are concentrated at the regions of discontinuity. The couplings have tended to fail at these localized regions of high stress. Moreover, the configurations of conventional splines or keyways caused the components of the coupling to be subjected to high tensile stresses. Since contemporary low-wear, self-lubricating plastic material have relatively low tensile strengths, it has not been possible to utilize these materials as components in conventional couplings. Because many torque couplings are used in applications where excessive wear is experienced, the use of low-wear, self-lubricating components would be highly advantageous.